1. Field of the Invention
The present invention relates to a positioning system; more particularly, to a positioning system capable of accurately arranging a mask on a substrate.
2. Description of Related Art
During the packaging process of the light-emitting diodes (LEDs), luminescent solution having phosphor powder is typically glued or coated onto an LED chip. For some coating processes, the LED chip is electrically connected to an LED substrate via a wire bonding process. Conventionally, a mask is manually arranged on the LED substrate that supports the LED chip. However, the wires may be touched by the mask during the manual procedure. As a result, the reliability of the LED packaging process tends to suffer. In addition, some small gap or clearances are usually present between the mask and the LED substrate. In other words, the mask and the LED substrate is not seamlessly arranged against one another. Hence, during the coating process, the luminescent solution can very easily leak to areas where coating and wire bonding processes are yet completed. Accordingly, the yield rate of the wire bonding process is reduced, as the wires of the light-emitting diodes tend to break easily during reliability tests, such as thermal shock or thermal cycle tests.